The present invention relates to the field of encoding and communicating barcode information.
A barcode is a machine-readable representation of data. Barcodes are typically printed on items, such as paper labels or packaging for goods, manufacturer's or retailer's coupons, or on tickets or passes such as airline boarding passes. Barcode scanners (also referred to as barcode readers) are used to extract information from barcodes. Barcode scanners are found in many different types of facilities including stores and supermarkets, airport security check-in and boarding areas, stadiums, libraries, test centers, conference centers, and in many other contexts. The use of barcode scanners has dramatically increased the speed and convenience of performing many commonplace transactions.
While typically printed on paper or other objects, barcodes may also be presented on the electronic displays of personal electronic devices such that the barcode can be read by a barcode scanner. While it can be useful to present coupons and other information in barcode form on the display screen of a personal electronic device, there are disadvantages. Some barcode scanners, for example, cannot reliably read barcodes displayed on certain types of displays because the contrast ratio between the bars and spaces shown on the display screen, which typically is a liquid crystal display (“LCD”), is not sufficient. Further, the physical dimensions and/or resolution of the display screen may also limit the size of the barcode that may be displayed at one time.
A technology that simulates barcodes using pulsed light and thereby overcomes various limitations of static screen-displayed barcodes is disclosed in, for example, U.S. Pat. No. 6,685,093 issued Feb. 3, 2004 to Challa et al. What is needed are improved techniques for communicating barcode information using a mobile device.